﻿using Microsoft.SqlServer.Server;

namespace CSharpTest.Vo
{
    public abstract class Stock
    {
        public abstract decimal NetValue { get; }
        
    }
    public interface IUndoable{
        void Undo();
    }

    public class TextBox : IUndoable
    {
        public virtual void Undo()
        {
            throw new System.NotImplementedException();
        }
        
    }

    public class TextBox2 : TextBox
    {
        public sealed override void Undo()
        {
            base.Undo();
        }
    }
}